Disconnecting and Reconnecting Links

Purpose:  A link may be disconnected from its parent node, without the link actually being removed.  That means that the child node can maintain the information on the conditional probability table it had with its parent, without actually being connected to the parent.  The intention is that later it will be reconnected to the parent, or more likely to some other node, before it is used for inference. It may be reconnected soon afterwards, or the node(s) may be placed in a library of net fragments and only reconnected when the library is used to build a new Bayes net.

How To:  To disconnect some links, select them and then choose Modify Disconnect Links or click the image\KnifeTOOL.gif toolbar button.  Each link will turn into a short stub connected to its child node, and labeled with the name of the link. If you have not previously named the links, then Netica will name them with the names of the parent nodes.  If you want to disconnect all the links entering some node(s), select the node(s) and choose Modify Disconnect Links.  You can also hilite individual links, right-click and choose Disconnect.

By Dragging:  If you want to disconnect a link while mostly maintaining its shape, first click on the link to select it.  Then click down on the hilited box at the end of the link (the end without the arrow), and drag it away from the parent node.  When you release the mouse button you will know that you have dragged the box far enough if the name of the link appears beside it.  All of the bends of the link will be maintained.

Child End:  A link cannot be disconnected from its child node.  That would not make sense, since a disconnected link is really just a “parent place-holder” to maintain the node’s relation (e.g. CPT) until it is connected up to a new parent.  To achieve the affect of disconnecting a link at the child end, it sometimes makes sense to do a link reversal, and then disconnect the link at the parent end.

Reconnection:  To reconnect a disconnected link to a new node, first click on the link to select it.  It will be outlined with the hilite color, and there will be a box of hilite color at the disconnected end of the link.  Choose Modify Reconnect Links.

You may disconnect a link from one parent and connect it to a new parent in one motion if you wish.

See also Link Reversals

See also Deleting Nodes and Links